Engine piston



Dec. 30, 24- 1,520,972

A. SPILLMAN ENGINE PISTON FICE.

ATENTOF ALBERT SPILLMAN, or nonrn'ronawanna, NEwYonx;

ENGINE Application filed February 1 To all whom it may concern:

Be it known that I, ALBERT SPILLMAN, a citizen of the'United States, residing in North Tonawanda, in the county of Niagara and State of New York, have invented new and useful Improvements in Engine Pistons, of which the following is a specification.

This invention relates more particularly to vthe pistons used in explosion enginesor motors.

One of its objects is the provision of a re-v silient self-adjusting piston of improved construction.

Another object is to provide the piston with simple and reliable means for returning the oil scraped from the cylinder walls by the piston back into the latter and thence into the crank case, with a view of preventing the oil from working past the piston into the top of the cylinder and avoiding fouling of the spark plugs and a smoking exhaust.

In the accompanying drawings: Figure 1 is a sectional elevation of the improved piston combined with a cylinder. Figure -2 is a side elevation of the piston taken at right angles to Fig. 1. Figure 3 is an enlarged vertical section on line 33, Fig. 1 Figure 4 is an enlarged vertical section on line 4-4, Fig. 2. Figure 5 is a horizontal sectionon line 55; Fig. 4. Figure 6 is an enlarged fragmentary sectional view taken on line 66, Fig. 1. p

Similar characters of reference refer to like parts throughout the several views.

10 represents the head of the piston which is provided with the customary grooves 11 for receiving the packing rings 12, and 13 the skirt or tubular body portion thereof. Integral .with the latter and extending inwardly from diametrically opposite sides thereof are the usual bearings 14, 14 for the wrist-pins of the connecting rod, not shown. In order to give the skirt the necessary resilience or contractile capacity to prevent scoring of the cylinder. it is provided at opposite sideswith transverse or substantially horizontal slots 15 located above. the

wrist-pin bearings. and angular slits 16 extending from points at or near one end of the horizontal slotsto a point below said bearings, as best shown in Figs. 1,2 and 4. These angular slits preferably extend in the same direction from the corresponding ends of the horizontal slots. The latter are formed in one of the ring grooves 11, preferably the rearmost or lowermost one, designated 11,

PISTON.

5, 1923. Serial No. 819,303.

and in those sides thereof at right angles to the sides containing the bearings 14, while the angular slitsextend downwardly around one side of said bearings and terminate at a point a suitable distance beyond the vertical axis thereof, as shown in Figs. 1 and Oblique longitudinal slits 17 may also be providedin the skirt, which are preferably arrange d substantially in line with the axes of the wrist-pin bearings and which extend from the base of the. angulaflslits to the lowenedge of the skirt. Z ,1 y,

' To obtain the best results, the ends of the horizontal slots 15 preferably terminate at apoint approximately ,forty. degrees from the axes of the 'wrist-pin bearings.

By slitting the piston in this manner, the

skirt is divided into resilient sections which yield more or less in response to the expandmg and contracting movements of the cylinder, maintaining a tight fit and at the same time preventing scoring of the'cyli-nder. In order to prevent the sectional skirt from collapsing or contracting below its normal diameter and remaining in suchposition and still permit it to expand and contract with the cylinder yieldable transverse connecting webs 18 are provided which are located at. one or both sides of the pistonand joined to the Skirt sections on opposite sides of the I oblique slits 17, as shown in Figs. 4 and 6.

If desired, one of these oblique slits may be om gted so as to leave that side of the piston ri 'i Located on the resilient or non-thrust side of the piston and connecting tliehead with the skirt thereof above and below the c0rresponding horizontal slot 15 is a longitu-' dinal web or bridge piece 19 which is preferably cast integral with the piston. The ends of this bridge piece are loe'ated a suitable distance above. and below the slot.

The lowermost ring-receiving groove 11 in which the horizontal slots '15 are located is preferably somewhat wider than the restantially the same width as saidlowermost groove. The several packing rings 12 seated in the grooves 11 are of a standard width lief space or oil-conducting passa e 20 is 7' left between one of the walls of sai groove 'maining grooves, and the slots are of sub-' and its ring, as shown in Fi 1, whereby any oil scraped from the wal s of the cylengine crank-case. The lowermost packing 1 ring functions as a valve during the reciprocation of the piston, so that on the down stroke of the latter said ring is compelled by the pressure acting against it to rise against the upper wall ot' its groove,thus leaving the necessary clearance below the lower edge of the ring to allow the oil to escape into and through the slots 15.

By providing such return slots or passages for the surplus oil, the latter is prevented from working past the top of the piston, avoiding smoking of the exhaust and fouling of the spark plugs. This also results in utilizing a larger amount of oil and a better lubrication of the piston, and eliminates the formation of carbon on the cylinder walls.

-As shown in Figs. 3 and 4, substantially upright stifiening posts 21 may he provided which connect the webs 18 with the underside of the bearings 14.,

I claim as my invention:

1. An engine piston comprising a skirt having wrist pin hearings and a head having packing ring grooves and a transverse slot formed in the bottom of one of said grooves and located in a side of the piston at right angles to the sides containing the wrist-pin hearingasaid skirt having a, slit arranged at an angle to said transverse slot and joined at-its upper end therewith, the lower end oat said skirt-slit extending around the lower side of the adjacent wristpin bearing and terminating at a point beyond its vertical axis.

ans engine piston, comprising a skirt having wrist pin bearings and a head having packing ring grooves and atransverse slot formed in the bottom of one of said grooves and located in a side of the piston at right angles to the sides containing the wrist pin bearings, said skirt having slits arranged at an angle to said transverse slots and joined at their, upper ends to the correspending ends thereof, said skirt-slits trending in the same directions and their lower i ends extending around the lower sides of said wrist-pin bearings and terminating at .n atlnlei fliesaine An engine piston, comprising a skirt havihgnvrist-pin hearings, and a head having transverse'slots located in those sides thereof at right anglesto the sides containing the wrist-pin hearings, said skirt having correspondingly trending slits joined at their upper ends to said transverse slots,

while their lower ends extend below the i ,aa evs Wrist-pin hearings and terminate at a point substantially in line with the vertical axes thereof, the skirt also having longitudinal slits extendin from the lower portion of the first named slits to the lower edge of the skirt, whereby the skirt is divided into yieldalole sections.

t. An engine piston comprising a skirt having wrist-pin bearings, a head having transverse slots located in those sides thereof at right angles to the sides containing the Wrist-pin bearin 5, said skirt having correspondmgly tren ing slits joined at their uper ends to said transverse slots, while their ower ends extend below the wrist-pin hearings and terminate at a point substantially in line with the vertical axes thereof, the skirt also havinglongitudinal slits extending from the lower portion of the firstnamed slits to the lower edge of the skirt, whereby the skirt is divided into yieldahle sections, and yieldahle means joining the portions of said skirt sections adjacent to said longitudinal slits.

5. An engine piston, comprising a skirt having wrist-pin hearings, a head having transverse slots located in those sides thereof at right angles to the sides containing the wrist-pin bearings, said skirt having correspondingly trending slits joined at their upper ends to said transverse slots, while their lower ends extend below the wrist-pin hearings and terminate at a point substantially in line with thevertical axes thereof, the skirt also having longitudinal slits extending from the lower portion of the first-named slits to the lower edge of till the skirt, whereby the skirt is divided into yieldable sections, and yieldable transverse tie members connecting said skirt sections and bridging said longitudinahslits 6. An engine piston, comprising a skirt having wrist-pin bearings, a head having transverse slots located in those sides thereof at right angles to the sides containing the wrist-pin bearings, said skirt having'correspondingly trending slits joined at their upper ends to said transverse slots, while their lower ends extend below the wrist-pin bearings and terminate at a point substantially in line with the vertical axes thereof, the skirt also having longitudinal slits extending from the lower portion oi? the firstnam'ed 'slits to the lower edge of the skirt,

pin bearings.

\v ALBERT SPlliLMANj 

